Australian scientists believe they've discovered the 'origin cell' of a common form of lung cancer that kills thousands of smokers and ex-smokers every year.
They've identified the cell which mutates when exposed to the harmful chemicals in cigarettes.
Using donated human tissue, they looked at the cells in the airway of the lung and noticed that when exposed to harmful chemicals like cigarette smoke, they would rapidly repair the damage.
This repair process was far more active in the lungs of smokers, and was prone to errors and mutations in the cell development.
The potentially life-saving discovery could mean earlier detection of squamous cell lung cancer, which accounts for up to 30 percent of all lung cancers.
The discovery was made by researchers at the Walter and Eliza Hall Institute in Melbourne, led by PhD student Clare Weeden and Dr Marie-Liesse Asselin-Labat.
Ms Weedon told RadioLIVE it's a positive step towards early diagnosis.
"We've discovered the cell which is thought to give to rise to a particular type of lung cancer, and there needs to be more work to figure out how to help patients. If we're able to detect the cancer earlier, that ultimately means good things for patient survival."